Cross-Cultural Adaptation of Persian Version of Scale of Oral Health Outcomes for 5-Year-Old Children.

OBJECTIVES
Indicators of oral health-related quality of life (OHRQoL) in children are widely adopted to evaluate the effects of oral problems. Recently, the scale of oral health outcomes for 5-year-old children (SOHO-5) was developed based on the children's self-reports. This study aimed to evaluate the validity and reliability of the Persian version of the questionnaire in a sample of Iranian children.


MATERIALS AND METHODS
This cross-sectional study was conducted on 160 children from four areas of Isfahan selected via non-random purposive sampling. After forward-backward translation of the questionnaire, content and face validity evaluation, a pilot test was carried out. Children forms were completed by interview, while parents forms were self-administered. Test-retest reliability was evaluated in 30 subjects. Construct validity, internal consistency and descriptive quality of life score were assessed with SPSS 18. The child-parent agreement was measured with correlation test and paired t-test (α=0.05).


RESULTS
The mean (±standard deviation) quality of life scores in children and parents were 2.3±3 and 1.3±1.9, respectively. The most prevalent impacts were difficulty sleeping and eating. The Cronbach's alpha coefficients were 0.82 and 0.67 for the child and parent versions, respectively. Significant correlation of the scores with the oral health rating, pain history and perceived need for treatment confirmed its construct validity (r: 0.4-0.6, P<0.05). The hypothesis of the agreement was not supported (P>0.05).


CONCLUSIONS
Based on the findings, the Persian version of SOHO-5 has acceptable reliability and validity for use in the pediatric population of Iran while there were some conflicts by parents.


INTRODUCTION
By expanding the concept of oral health-related quality of life (OHRQoL) within the scope of outcome measures, individual self-reports have been emphasized in addition to traditional disease diagnosis [1]. Oral health related quality of life evaluates impacts of oral pain and dysfunction on psychological and social performance. Various tools have been designed to measure the qualitative experiences and relationship between oral problems and personal and social life. Children's oral health affects their feeding and social relationship as well as speaking and smiling [2]. Despite the improvement of oral health, dental caries is a public problem all around the world and also in Iran. The mean dmft of 4.13 in 3-6 year-olds and 61% prevalence of childhood caries have been reported in different areas of Iran [3,4]. The oral health national survey in 2012 showed that only 12.7% of primary teeth were caries-free among [5][6] year-old children [5]. Therefore, preschool children are still among the prioritized target groups for oral health policies. According to

MATERIALS AND METHODS
The study protocol was approved in the ethics committee of Isfahan University of Medical Sciences (code:393714). By obtaining permission from questionnaire developer, children and parents forms, in addition to the prompt response card were translated by two bilingual translators, independently, to Persian in accord with the standard guidelines. The backtranslated version was compared with the original forms to determine the semantic equivalence. After reaching a consensus, a single copy was prepared by the translation team and researchers. In terms of face and content validity, the translated version was evaluated by a panel of experts including pedodontists, public health dentists and child psychologists. According to Lynn's method, relevance of each question was measured with a scale of 1: completely irrelevant to 4: completely relevant [15]. Content validity index for each item was calculated by the proportion of items with the scores 3 or 4 and the cut-off point of 67% by experts. Overall, scalecontent validity index (S-CVI) was reported by both universal agreement (ua) formula and overall scale CVI by average (ave) [16]. Considering the final changes, the last draft of Persian version was pilot tested in 15 children in the age of 5-6 years for comprehensibility of questions, response time and the way of communicating with children. Consequently, the psychometric properties of Persian SOHO-5 were assessed in a sample of target group. Based on previous standard deviation of 3.2 [14], α equal to 95% and measurable error of 0.5, a sample of 160 children in the age of 5-6 years were recruited for the descriptive study from four kindergartens (approximately 40 from each kindergarten) of different social regions of Isfahan city. They were selected randomly according to the high (areas 3 and 5) and low socioeconomic class (areas 10 and 12) municipal subdivisions. Written informed consent was obtained from children's parents or guardians. The children form was filled out by a face-to-face independent interview by asking children about pain experience and the effects of oral status on their daily activities. Children were queried about any experience of difficulty in eating, drinking, smiling (due to dental caries and appearance) and sleeping. The answers were recorded using a 3point scale (no: 0, a little: 1 and a lot: 2). Parents forms were given to parents and collected after one week. The self-administered questionnaire was about their child's difficulties in eating, playing, speaking, sleeping and avoiding smiling due to tooth decay and unesthetic appearance of teeth negatively affecting their self-confidence. Response options were in the form of a Likert scale: Never: 0, a little:1, moderate: 2, a lot: 3, a great deal: 4. The SOHO-5 scores were calculated as the sum of response scores for each questionnaire. This form had three parts including current toothache in children, the impact of child's teeth on daily life (seven items) and the effects of dental health on the family (11 items). After collecting data, similarity between parents' and children's responses about evaluation of the impact of oral problems on quality of life was assessed. For this purpose, six common questions in two forms were selected and the two questionnaires was re-coded in a three-point scale (never=0, a little and moderate=1, a lot and a great deal=2). Therefore, the score for the evaluation of both forms was calculated from 0 to 12. To assess the construct validity of the questionnaire, standard global rating questions were asked. For the children, satisfaction with oral health (not happy=2, a little happy=1 and very happy=0) and presence of dental cavities (no=0, yes=1) were questioned. For the parental questionnaires, the following oral health ratings (excellent=0, very good=1, good=2, fair=3, poor=4), satisfaction with child's oral health (very happy=0 to very unhappy=4), and the child's perceived dental treatment needs (no=0, yes=1) were included. Subjective dental health questions as current and experience of toothache were asked for testing discriminant validity. Data analysis: The collected data were analyzed using SPSS software version 18. The final overall scores ranged from 0 to 14 for the child and from 0 to 28 for the parents version with seven questions. The score of impacts on the family was reported in the range of 0 to 44 for the final 11 items. Answers of "I cannot remember" or "I do not know" were considered as missing data. For the self-administered questionnaire, missing data were replaced by nearby points' median to calculate the total scores. Quality of life mean (standard deviation) scores from children and parents forms and the frequency of each dental problem were reported as descriptive statistics. Moreover, the test-retest reliability of SOHO child form was calculated after it was completed by 30 children via an interview in a two-week interval. Internal consistency of the questionnaire was assessed by Cronbach's alpha coefficient and the inter-item correlation. Construct convergent validity was tested through associations between the SOHO-5 scores and the global ratings using Spearman's correlation coefficients. Comparing the means between the children with current/history of toothache, cavity or perceived need to treatment was done for discriminant validity. The agreement between

Content validity index for items of children form
indicated that all the statements with exception of discomfort in tooth eruption (Q1) had a mean index of more than 3 with 83% acceptable response rate. In children form, the S-CVI was 0.5 (ua) and 0.89 (ave). Hence, the first question was omitted and the final questionnaire was changed to six items with a response rate of zero to 12. In the parents form, question 22 about being jealous of family member by 66% acceptable CVI response rate and question 24 about blaming the parents by child were omitted. In parents form, the S-CVI was 0.62 (ua) and 0.96 (ave). The questions 21 and 23 were merged due to content similarity. The pilot test showed that children preferred to express their feelings or experiences verbally rather than pointing to the cards with schematic pictures, and average response time was seven minutes for each interview. Almost all the subjects answered without requiring repetition or rewording. A total of 82 boys (51%) and 78 girls enrolled in the main study, and the mean of quality of life score was found to be 2.3±3 with a range of 0-14 in children form. The most common problems were difficulty in sleeping (32%) and eating (33%), while the least common problem was avoiding smiling due to tooth decay (11%). Approximately, 90% of the parents questionnaire was answered (response rate) and the parental SOHO score ranged from 0-9 with a mean of 1.3±1.9. The score of the family impact section with 84% response rate showed a mean of 8.3±7 with a range of 0-26. Nearly, 41% of the children and 46% of the parents reported no oral impacts of daily living but 88% of them had encountered problem in their family. Children's SOHO mean score was significantly higher in boys than girls (P=0.027), although this relationship was not significant in parents form. However, the parents' score of quality of life was more in lower socioeconomic regions than in upscale areas (P<0.001) but this was not significant in case of children. In terms of internal consistency reliability, Cronbach's alpha coefficient was 0.82 and 0.67 in children and parents' questionnaires, respectively (Tables 1 and 2). To evaluate the reliability over time, test-retest showed ICC (95% confidence interval) of 0.8 (range 0.6-0.9) for parents form. The two-way random effect model analysis showed a P<0.001. In addition, the mean difference test (paired sample t-test) at two times showed no significant difference (P=0.6) over time. The construct convergent validity showed that the SOHO-5 total score was associated significantly and in the expected direction with two global rating questions for parental proxy reports (Table 3). Eating and sleeping items were significant subscales with moderate correlation. This was not supported in the child version when the relation between the question about "satisfaction with oral health" and total score was analyzed (P>0.05). The discriminant validity was clarified by significant mean differences between the scores of quality of  (Tables 4 and 5).
The findings of agreement analysis between six common items in children and parents forms demonstrated that in all items, correlation between children and parents responses was at the poor or fairly poor extent. The highest reached agreement was at the domain of impacts on sleeping (ICC of 0.28, P=0.02). The mean overall quality of life score in the common items was 2.5±1.8 and 1.2±1 for children and parents, respectively, and showed a significantly lower score for parents compared with children (P=0.001, paired t-test analysis).

DISCUSSION
This study was designed with the aim of preparing and validating the SOHO-5 Persian version in 5-year-old Iranian children living in Isfahan. The quality of life questionnaire specialized for this range of age was surveyed in terms of face, content, and construct validity. In this study, a self-reported OHRQoL measuring tool for children was prepared for the first time in Persian language.
The psychometric properties of the SOHO-5 were satisfactory and provided strong support for its reliability and validity. The range of inter-item correlation coefficient was 0.15-0.73, which was above the recommended level of 0. Global health rating and perceived oral health or satisfaction with teeth are the general indices that are implicated for testing the convergent construct validity. In our study, the questions which have been utilized to evaluate construct validity in parents version showed good result, in spite of the non-significant answers due to the children's happiness with their teeth. Difficulty in eating and sleeping were the most relevant problems with general oral health perception and satisfaction in our study. Moreover, the correlation between child's toothache with difficulties in eating, sleeping and avoiding smiling due to appearance was similar to the results of the Brazilian study [14]. The highly expressed eating and sleeping subdomains in our study supported understanding of more tangible terms. Recently, we encountered a rapid change in the structure of personal and family life because of digital technology. With the rapid advancements in the devices like smartphones or digital tablets, there is an explosion of electronic media and learning packages directed at preschool children in many societies. It is stated that both positive and negative impacts on children's development would be seen in physical, cognitive and social domains [19]. Thus, constructing subjective measures for young children would be challenging in future. To date, nearly most of the research on OHRQoL measures has established on the parents' proxy reports. While the parents' expression may not necessarily be identical to those of their children, the relevant studies have shown weak or moderate associations between them [7,18,20]. Although another study on SOHO-5 revealed that parents reported significantly worse OHRQoL than their children [18], our results showed overall better quality of life statements in parents compared with their children's reports while the agreement was only in the difficulty in sleeping. Therefore, the newly introduced tool for measuring the quality of life by children reports should be evaluated in large or diverse samples and in symptomatic patients to clarify the real competencies. However, it is controversial whether there is an accurate patient-based tool compatible with clinical manifestations in children, and the statistical validity and reliability of the instrument may not guarantee the fact. Discriminant construct validity of both children and parents forms of the questionnaire should be tested in future studies.

CONCLUSION
According to the results of this study, Persian version of SOHO-5 is acceptable for 5-year-old Persian language children as a complementary assessment measure while it could not be a substitute tool.